Collapsing tap and similar tool.



F. A. EBRINGTQN. I COLLAPSING TAP AND SI MILAR TOOL. APPHCATION FILEQ FEB. I2. 19H- I IN Patented Oct. 3, 1916.

o 'rn earns FRANKLIN a. nnme'ron, or srnrLE'ron, NEW YORK.

COLLAPSING TAP AND SIMILARTOOL.

Specification of Letters Patent.

Patented Oct. 3, 1916.

Application filedj'ebruary 12, 1914.. Serial No. 818,283.

To all whom it may concern Be it ,known that I, FRANKLIN ALFRED ERRINGTON, a citizen of .the United States, residing at Stapleton, in the county of Richmond and State of New York, have invented certain new and useful Improvements in Collapsing Taps and Similar Tools, of which the following is a specification.

My invention relates broadly to interchangeable means of rigidly determining the cutting diameter .of'ja tap or similar tool, as distinguished from instable, adjustable means .of varying the cutting dimet th reo an th Pri cipa Object of my in entio is t Pr v d a mpl means of collapsing a plurality .of screwcuttin chasers by utilizing the spiral coaction of thescrew-threads during the cutting operation of the teeth of the chasers'with the threads thereby cut in the work in such a manner as to move longitudinally of the supporting body either ,the chasers or the means that determine their cutting diameter, and thereby collapsing the chasers so that the tap can be withdrawn from the work without stopping or reversing the direction of rotation of .the... driving means; and my invention further consists the novel details of improvement that will be more fully hereinafter set forth .and then pointed out in the claims.

Reference is to be had to the accompanying drawings, forming a part thereof, wherein Figure 1 represents a vertical cross-section of a device embodying my invention, the parts being shown in the cuttinglposr' tion of the aws; Fig. 2 is a horizontalcrosssection of Fig. l on the line 2-2, showing the transverse arrangementof the parts in the cutting position; Fig.3 is a similar view toFig. l, exceptthat the parts are shown in the collapsed .position; ,and Fig. ,4: is a plan viewof thecutting end of the device, showing the jaws in the collapsed position.

Similar numerals and letters of reference indicate corresponding parts in the several views. V

A body lis shown provided atits rear or inner end with a shank 1 for connection with suitable driving means, at the outer end the periphery of the body is indented bya multiplicity of longitudinal grooves 1, adapted to receive jawspr chasers 2. The body 1 is preferably provided with anaxial bore P, and intercommunication between the transverse bores 1 may be reduced in size according to the cutting diameter determined upon for thejaws 2. The outer end of core 3 is shown screw-slotted for the ready clamping of the core in place, or remov ng the core from the body 1; and the inner end of the core is preferably beveled, for a purpose hereinafter described. Between the core 3 and independent of jaws 2 I have interposed a longitudinal series of thrust-blocks 4, located in the transverse bores 1 the outer ends of the thrustblocks 4 extending outwardly beyond the bottom surfaces of the longitudinal grooves 1, to provide therein a longitudinal series of projections with indentures therebetween, the outer end surfaces of the thrust-blocks 4 providing external thrust- ,faces 4? adapted to bear upon a corresponding longitudinal series of projections and indentures provided on the under or inner surface of the jaws 2 the inner surfaces of the aw-pro ections providing in- .ternal thrust-faces 2 adapted to bear upon the external thrust-faces 4 when the jaws are in the cutting position (see Fig. 1 and Fig. 2.)

The jaws 2 are preferably held in their respective grooves 1 concentrically of body 1 by a spiral band-spring 5, the ends of which are joined together; and the aws 2 are shown provided with a spring-groove 2 extending across the outer surface of the jaws. The jaws 2 are sufliciently extended beyond the periphery of body 1 to permit the retaining-spring 5 to exert a concentric pressure upon them, even when in the collapsed position. An abutment .or, pin 6 is provided (see Fig. 4) for the spring 5 to,

slip over and thereby hold the jaws in the cutting position; and I believe it is preferable to provide a multiplicity of these abutments 6 to insure holding the spring 5 and by it the jaws 2 evenly in the cutting 7 position. To protect spring and also to facilitate the closing of jaws 2 1 have shown the spring 5 surrounded by a closingring To facilitate the manufacture of the device and to provide a true surface for all the jaws 2 to abut against when presented against the work, I have preferably slipped a hardened ring 8 over the body 1, said ring abutting against a shoulder 1 provided on body 1 for that purpose. The jaws 2 are then slipped into their respective grooves 1, the rear surfaces of the jaw-projections be ing preferably beveled to run up over the projecting ends of the thrust-blocks 1 as said jaws are pushed inwardly of body 1 along said grooves 1"; and the front surfaces of the jaw-projections are shown extending at right angles to the axis of body 1, to catch against the projecting thrust-blocks 4: when the jaws 2 have moved forward to the collapsed position (see Fig. 8.) The spring 5 (within its ring 7) is preferably slipped over the jaws 2 while they are in the collapsed position shown in Fig, 3, the spring 5, passing over the screw-threaded portions of the jaws until said spring meshes with the grooves 2 provided in the jaws to receive it.

To bring the parts into the cutting position' shown in Fig. 1, the operator pushes the ring 7 inwardly along body 1, and with it the spring 5 and jaws 2, the sloping sides of the jaw-projections ascending the thrustblocks 4:, until the internal thrust-faces 2 of the jaws slide into line, transversely of body 1, with the external thrust-faces of blocks a, said thrust-faces continuing to increase their bearing upon each other until the rear ends of the jaws abut against the thrust-ring 8, whereupon the spring 5 shall have slipped over abutment 6, thereby looking the parts in the cutting position shown in Figs. 1 and 2.

When it is desired to change the cutting diameter of jaws 2, the core 8 can be removed and a smaller or a larger core put in its place, the inner end of the core 3 being beveled to push the thrust-blocks 4e radially outward as the core 3 is pushed along the bore 1 into its proper position, where it is immovably clamped by the screw-threads in said bore and on said core for that purpose.

'Should the biggest core 8 admissible into bore 1 still leave the cutting diameter of the jaws 2 too small for the work contemplated, the thrust-blocks a can be changed for longer ones; or even if the axial bore 1 and its core 3 were omitted, the diameter of the jaws could be changed by a corresponding change in the projection of the thrustblocks 1 above the bottom surfaces of the grooves 1 by a corresponding change in the size of the thrust-blocks 4. i

' VVhenapplying my invention to a collaps- 7 nally screw-threaded as shown in the drawings, upon the rotation of either the device or of a suitable piece of work having a suitable aperture to be tapped, the chasers 2 will out screw-threads into the walls of said aperture in the work upon the presentation of the device thereagainst, and the position of the chasers 2 relatively to body 1 will remain constant until the relative movement of the device and the work toward each other is stopped by any suitable meansg as, for instance, by using the outer end 1 of the body as a stop to encounter the bottom surface of the aperture being threaded, whereupon the continued rotation of the rotative member (either body 1 or the work being operated upon) will cause the chasers 2 to continue cutting, while at the same time the screw-threads of the chasers 2 will draw the chasers 2 longitudinally of body 1 during the cutting operation independently of the thrust-blocks f by the spiral coaction of the screw-threads of the chasers with the threads already out in the work until the internal thrust-faces 2 of the chasers 2 pass out of line transversely of body 1 with the external thrust-faces P of the thrust-blocks l, whereupon the jaws 2 will slide inwardly radially of body 1, the projections 2 of the chasers passing within the plane of their respective associate external'thrust-faces 41 into the indentures therebetween, and this inward radial movement of the chasers continues during the collapsing operation until the cutting teeth clear the threaded walls of the aperture in the work, whereupon the de-' vice can be withdrawn from the threaded direction of rotation of the rotative member.

Having now described my invention, what I claim is 1. The combination of a body having a plurality of longitudinal grooves in its periphery and cutting jaws located in said grooves the bottom surfaces of the grooves being indentedby a longitudinal series of transverse bores to receive a corresponding series bf thrust-blocks located under and independent of the jaws and projecting outwardly beyond the bottom surfaces of the grooves, thereby providing therein a longitudinal series of external thrust-faces with i11- dentures therebetween, the inner surfaces of the jaws being 'providedwith a corresponding longitudinal series of projections with indentures therebetween, theinner surfaces of said jaw-projections providing internal thrust-faces during the cutting opternal thrust faces during the cutting operation, said jaws being movable longitudinally of the body independently of said thrust-blocks during the cutting operation to bring said internal and external thrustfaces out of line with each other to collapse the jaws, substantially as described.

2. The combination with a body having a plurality of longitudinal grooves in its periphery, the bottoms of said grooves being pierced by a longitudinal series of bores extending transversely of the body, thrustblocks located in said bores, a sizing-core centrally located in said body, screw-cutting jaws located in said grooves, said core and said jaws being movable the one longitudinally of the other during the cutting operation, the longitudinally movable member being provided with a series of projections and indentures to coast with said thrust-blocks to collapse said jaws, substantially as described.

3, The combination with a body having a plurality of longitudinal grooves in its periphery and cutting jaws located therein, the bottoms of said grooves being pierced by a series of bores extending transversely of the body to afford intercommunication between said grooves, of a longitudinal series of thrust-blocks located in said transgrooves, thereby providing therein a longitudinal series of external thrust-faces with lndentures therebetween, the inner surfaces of the aws being provlded with a corresponding longitudinal series of projections with indentures therebetween, the inner surfaces of said jaw-projections providing internal thrust-faces that bear upon said external thrust-faces during the cutting operation, said jaws being movable longitudinally of the body independently of said thrustblocks during the cutting operation to bring said internal and external thrust-faces out of line with each other to collapse the jaws, substantially as described.

FRANKLIN A. ERRINGTON.

Witnesses:

F. J. Goonmox, A. C. STooK.

copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

